DITA (topicref) overwrites Font properties

I save my DITA topic files as fm file rather than xml in order to be able to modify the font properties such as color, size, angle etc. The changes stay in the original fm file. However, when I use topicref in a ditabookmap to insert the book chapters, those changes are overwritten in the published PDF with the default DITA format. Is there a way to keep the changes in the final book or I need to customize the original EDD?

Hadi